Shunt centering and locking apparatus



May 26, 1970 R. H. JACKMAN SHUNT CENTERING AND LOCKING APPARATUS 2 Sheets-Sheet 1 Filed Jan. 31, 1969 s H I 0 W R m mn N M NNIE NM M mm m m U M 3 h a \N 3 t a: A a 9 g 2 VW Y mu MW IB 9 v 3 rho 8 7 WW T QN N0 MM May 26, 1970 I R. H. JACKMAN 3,514,732

SHUNT CENTERING AND LOCKING APPARATUS Filed Jan. 31, 1969 2 Sheets-Sheet 2 FIG. .5 94

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BY 36 M United States Patent O 3,514,732 SHUNT CENTERING AND LOCKING APPARATUS Robert H. Jackman, Crystal, Minn., assignor to Twentieth Century Manufacturing Company, Minneapolis, Minn.,

a corporation of Minnesota v Filed Jan. 31, 1969, Ser. No. 795,486 Int. Cl. H01f 21/06 US. Cl. 336-133 7 Claims ABSTRACT OF THE DISCLOSURE A movable sliding shunt type of welder including a pair of shunting members comprising a pair of frame members housing shunts for movement thereof, a leverage arm moving said frame members, a U-channel member supporting each of said frame members, an inverted U-channel member overlying each of said frame members, said frame members and said channel members being disposed within the core of said welder, said frame members and said channel members respectively having beveled mating surface portions, a member bridging said core bearing against engaged end portions of the upper of said channel members, and securing means in connection with said core applying pressure to said bridge member to clamp said channel members against said frame members to respectively center and lock said frame members and the shunts therein in operating position.

TECHNICAL FIELD BACKGROUND AND SUMMARY OF THE INVENTION With reference to a movable shunt type of welder there is a tendency for a strong vibratory motion of the shunt resulting from lateral forces with the welder in operation and there is a considerable amount of attendant noise. It is desirable to have a simple and easily operated structure for centering the shunt with respect to the coils and the enclosing core to achieve a null position and for securing and holding the shunt relatively free of vibration. The purpose of the invention herein is to provide a simple and easily operated means for accomplishing the above desired results.

To the end of providing a simple and effective structure for the movement, positioning and locking of a shunt, a frame is provided to house the shunt, a channel member seated within the core of the welder supports said frame, an inverted channel member overlies said frame, the mating portions of said frame and said channel members are beveled whereby said frame is naturally self-centered between the legs of the channel members and between the legs of the core and overhead pressure is applied against said overlying channel member to lock said frame in position and a lever arm is utilized to easily move said frame when said pressure is relieved.

It is an object of this invention therefore to provide means for the self centering of the shunts in a null or balanced force position.

It is more particularly an object of this invention to provide means for locking said shunts against all directional tendency to vibrate.

It is also an object to provide a very simple locking and unlocking means for said shunts whereby said shunts are supported freely for readily adjustable movement in unlocked position.

It is also an object of this invention to use a minimum amount of core area in providing means for supporting said shunts and holding the same in locked position.

These and other objects and advantages of the invention will be set forth in the following description made in connection with the accompanying drawings in which like reference characters refer to similar parts throughout the several views and in which:

FIG. 1 is a view in side elevation with a portion thereof in section and portions thereof being indicated by dotted FIG. 2 is a view in vertical cross section taken on line 22 of FIG. 1 as indicated;

FIG. 3 is a view in vertical cross section taken on line 3-3 of FIG. 2 as indicated, and a broken portion thereof is shown in dotted line;

FIG. 4 is a horizontal section taken on line 4-4 of FIG. 1 as indicated; and

FIG. 5 is a vertical section taken on line 55 of FIG. 3 as indicated.

DESCRIPTION OF A PREFERRED EMBODIMENT With reference to the drawings, the welding structure embodying the subject matter of the invention herein is indicated generally by the reference numeral 10. This invention relates particularly to a welder having a sliding shunt and more particularly the embodiment thereof presented herein shows a structure comprising a pair of sliding shunts.

An external housing 12 is merely indicated by dotted line in FIG. 1 as its particular design is not essential to the invention herein.

It will be understood that the invention herein is applicable to various configurations of welding cores and is here shown in connection with an upright E-type of core 14 conventionally formed as a laminated structure comprising outer legs 15 and 16 and a central leg 17, said legs bounding windows 20 and 21.

Conventional primary and secondary coils 23 and 24 are mounted in spaced relation onto said center leg 17.

Disposed between each of said coils and respectively extending transversely through the windows of said core are shunting members 27 and 28.

Shunting member 28 comprises a frame of spaced elongated plate members 30 and 31 having inclined or beveled longitudinal edge portions, 33, 34 and 35, 36. Disposed between said plate members at one end portion thereof is a shunt 37 having a length substantially the width of said core 14. Said shunting member 28 has a length such that said shunt may be fully withdrawn from or fully disposed within said core. A non-magnetic spacing member 38 is disposed between said plate members '30 and 31 for substantially the remainder of their length.

Preferably there is a small space or gap between said shunting member 28 and the adjacent walls of said legs 15 and 17, as indicated in FIG. 2, with, said gap being on the order of 0.025 inch.

Shunting member 27 has a construction identical to that of said shunting member 28 and the various parts thereof are not here specifically described.

Disposed within said windows 20 and 21 are channel members 35 and 36 adapted to support and center said shunting members 27 and 28. Said channel members are adapted to be supported within said windows 20 and 21 extending upwardly at either side of the portions of said coil 24 which are at either side of the center leg 17. Said channel members extend outwardly somewhat of either end of said core 14, as indicated in FIG. 1. Said channel members conform to said windows having a small gap or space therebetween. Said channel members have base portions 38 and 39 and respectively have leg or side wall portions 40, 41 and 42, 43 extending upwardly therefrom to engage the lower sides of said shunting members 27 and 28. The inner upper edge portions 45, 46 and 47, 48 of said channel side wall portions are inwardly inclined or beveled to mate with the corresponding engaging side edge portions of said shunting members 27 and 28. Preferably said beveled edge portions of said shunting members and of said channel members are inclined at an angle of degrees.

Disposed above said shunting members 27 and 28 as mirror images of said channel members 35 and 36 are inverted channel members 52 and 53 having base portions 56 and 57 disposed adjacent the upper walls of said windows 20 and 21 and respectively have depending leg or wall portions 59, 60 and 61-62. The lower inner edge portions 63, 64 and 65, 66 of said respective wall portions will mate with the engaging beveled edge portions of said shunting members 27 and 28. Said channel members 52 and 53 merely rest upon said underlying shunting members and have a length such as to have their end portions 56a, 56b and 57a, 57b extend beyond the ends of said core 14 for a short distance. Said channel members 52 and 53 fit loosely within the upper portions of said windows 20 and 21 having a small space about the sides and base thereof and having the walls thereof disposed at either side of the portions of said coil 23 which are at either side of said central leg 17.

Thus the shunting members 27 and 28 are supported by the channel members 35 and 36 and in turn support 'the channel members 52 and 53. Said shunt members are freely movable transversely of said core between said opposed channel members.

Overlying or bridging said core 14 is a locking member 90 which may be variously formed and is here shown comprising side wall portions 91 and 92 extending along either end of said core to rest upon the extended end portions of said channel members 52 and 53. A top or web portion 94 extends between said wall portions to be integral therewith. Said Web portion is shown forming a slot to permit a screw rod 97 to extend upwardly centrally therethrough having its lower end portion 98 secured as by welding to the top of the core 14. Said screw rod will extend upwardly through the housing indicated in FIG. I. Said locking member in effect as here describe forms a channel-like member.

A tubular member 99 extends upwardly of said screw rod 67 having its lower end bearing against said web 94 and having'its upper end engaged by a hand wheel or knob 101 carried by said screw rod. Thus said hand wheel 101 will be threaded downwardly on said screw rod to exert pressure against said locking member 90 by means of said tubular member and in turn said locking member 90 will exert pressure against the extended end portions of said channel members 52 and 53 to lock said shunting members 27 and 28 between said upper and lower channel members.

Next will be described the apparatus shown here for adjustably moving said shunting members 27 and 28 with respect to said core 14.

A cross bar or rod connects adjacent ends of said shunting members 27 and 28. An elongated lever 77 is provided which has a short arm 78 rigid therewith and adjacent one end thereof having its free end 79 pivoted to said core 14 by a nutted screw 80 which may conveniently be welded at one end to said core. A link 82 is shown pivotally connecting one end of said lever 77 and an adjacent extended end 75 of said cross bar 75. Another link 84 extends upwardly from the other end of said lever 77 having a knob 86 at its free end. It is contemplated that the levers described will be contained within an ap propriate housing which here is merely indicated by the reference numeral 12 and that said knob 86 will extend outwardly of said housing as through the slot 88 and will releasably engage the housing adjacent said slot for locking engagement.

Appropriate indicia will be present on the housing adjacent said slot for positioning said knob in adjusting said shunting members 27 and 28 to provide desired welding current.

The operation of the above structure is quite clear from the description given.

There is thus an essential yet simple centering and locking relationship established between said shunting mem bers 27 and 28 and the adjacent locking channel members.

With current running through the core, lateral forces are generated which unless balanced cause a substantial vibration which develops a good deal of noise and chatter. The structure herein is intended not only to provide simple adjustment means for adjusting the position of the shunts carried by said shunting members 27 and 28 with respect to the core and the welding current, but there is also provided a simple but very effective means for avoiding a good deal of the chatter and noise by balancing the lateral forces generated by the current. This is accomplished by effectively centering the shunting members. This centering action is accomplished by the self-centering action resulting from the mutual engagement of the mating beveled edge portions of said shunting members and said locking channel members. Pressure applied by operation of the hand wheel 10-1 is the only manual action required. The shunting members and said locking channel members find their own mutual centering position and they are held in such position by the tight effective clamping action of said hand wheel bearing as it does by means of the tubular member 99 against the locking member 90 which in turn bears against the upper extended end portions of the channel members 52 and 53.

Thus with the centering of the shunting members, the lateral forces are balanced out and a null position is achieved whereby chatter and other vibratory noises are greatly reduced over what would otherwise be experienced.

The structure herein described has been found to have very satisfactory performance.

What is claimed is:

1. A shunt centering and locking means for a welding apparatus having in combination,

a core having a primary and a secondary coil mounted thereon in spaced relation,

a shunt disposed between said coils,

a frame having said shunt disposed therein, said frame having beveled edge portions,

means underlying said frame within said core having beveled edge portions mating with engaging beveled edge portions of said frame,

means overlying said frame within said core having beveled edge portions mating with engaging beveled edge portions of said frame, and

means carried by said core releasably locking said frame and said shunt therein between said first and second mentioned means, said engaging beveled edge portions self-centering said frame and said shunt therein.

2. The structure set forth in claim 1, wherein said underlying and said overlying means respectively comprise channel members having adjacent free end portions and having said frame disposed between said free end portions.

3. The structure set forth in claim 1, wherein said last mentioned means comprises a member extending across the top of said core having depending portions engaging said overlying means,

a rod carried by said core extending upwardly of said last mentioned member,

means carried by said rod bearing against said last mentioned member, and

locking means carried by said rod engaging and pressing said last mentioned means against said last mentioned member.

4. A shunt centering and locking means for a welding apparatus having in combination,

a core comprising a central leg having a primary and a secondary coil mounted thereon in spaced relation,

a window in said core at either side of said center leg,

a shunt disposed within each of said windows between said coils,

frames respectively including said shunts having beveled edge portions formed along the longitudinal edges thereof,

supporting members disposed within said core respectively underlying said frames and having beveled edge portions engaging corresponding beveled edge portions of said frames,

members disposed within said core respectively overlying said frames and having beveled edge portions engaging corresponding beveled edge portions of said frames,

said frames and said shunts therein being movable transversely of said core between said supporting and said overlying members, and

means carried by said core engaging said overlying members releasably locking said frames and said shunts therein between said overlying and said supporting members whereby said engaged beveled edge portions self-center said frames and said shunts therein with respect to said core.

5. A shunt centering and locking means for a welding apparatus having in combination,

a core having a central leg therein having primary and secondary coils mounted on said leg in spaced relation,

a pair of shunting members comprising shunts being respectively disposed between said coils at either side of said central leg and being movable transversely of said core,

said shunting members respectively having beveled side edge portions,

means underlying each of said shunting members having beveled edge portions mating with engaging like edge portions of said shunting members,

means overlying each of said shunting members having beveled edge portions mating with engaging like edge portions of said shunting members,

means carried by said core engaging said second mentioned means, and

releasable locking means engaging said last mentioned means to bear against said second mentioned means to self center said shunting members with respect to said core and to lock the same between said first and second mentioned means.

6. The structure set forth in claim 5, wherein said third mentioned means comprises a member overlying said core having depending portions engaging said overlying means.

7. The structure set forth in claim 5, including a transverse elongated member connecting said shunting members at one end thereof,

linkage extending from said elongated member to a control knob, said linkage being disposed at an angle to said elongated member whereby operation of said knob moves said shunting members transversely of said core.

References Cited UNITED STATES PATENTS 1,098,549 6/1914 Barnum 336-133 2,091,366 8/1937 Klinkhamer 336133 XR 2,173,735 9/1939 SOla 336-133 XR 2,265,980 12/1941 Beger 336-133 XR 3,091,744 5/1963 Owen 336133 XR THOMAS J. KOZMA, Primary Examiner 

